Dumb question about step

[A. Scottedward Hodel]

The current step function is the second iteration in the Octave  
Control Systems Toolbox (OCST).  In our first iteration, we followed  
the syntax you suggest, e.g.,

step (num,den)
step(num,den,T)
step(zer,pol,k)
step(zer,pol,k,T)
step(A,B,C)
step(A,B,C,D)
step(A,B,C,D,T)

etc.

Because of the ambiguity in arguments (3 arguments: is it a tf , zp,  
or ss?) etc., the interpretation of input arguments was a problem and  
took up the bulk of each m-file.  In our second iteration, we went to  
a more object oriented approach,

step(tf(num,den))

so that there was no question what the input data format was.   
Shortly thereafter, MATLAB also released object oriented toolboxes.   
(I am sure we were both working on our approaches in parallel).

It is possible to rewrite the routines to accept both the new syntax  
and the old syntax, but it would require some  care and testing, and  
that would not be a trivial effort.  (That is to say, I probably  
won't be the one to do it.)

Yours,

A S Hodel  http://www.eng.auburn.edu/~hodelas

On Feb 2, 2008, at 5:40 AM, Giuseppe Marullo wrote:

> Javier,
> many thanks about your answer. This will solve my problem (it works  
> now) but
> I am wondering if there is a way to use directly matlab sentences.
> I know it is my fault not knowing much and not wanting to dig  
> deeper than
> the minimum but
>  it could be great to be able to handle at least the basic stuff  
> without
> having to change it.
> Is there any compatibility switch that will turn octave into a  
> "strict"
> matlab clone?
>
> Thanks again,
>
> Giuseppe
>
> -----Original Message-----
> From: Javier Arantegui [mailto:javier.arantegui at gmail.com]
> Sent: Saturday, February 02, 2008 12:22 PM
> To: giuseppe at marullo.it
> Cc: help-octave at octave.org
> Subject: Re: Dumb question about step
>
>
> Hi!
>
> On Feb 2, 2008 10:18 AM, Giuseppe Marullo <giuseppe at marullo.it> wrote:
>> step(num,den)
>
> That's easy. You should user the function tf() to define your transfer
> function. Type this instead:
>
> step(tf(num,den))
>
> Or define it like this:
>
> G=tf(num, den)
>
> and then:
>
> step(G)
>
> To view your function transfer, use sysout():
>
> sysout(G)
>
>
> Javier
>
>
> --
> Lee mi blog: "Un pequeño paso para Neil" http://up3n.wordpress.com/
>
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